The present invention relates to a high quality, high gain dual channel differential amplifier exhibiting high common mode rejection characteristics. More particularly, the invention relates to such an amplifier fabricated as a large scale integrated circuit utilizing MOS field effect technology and specifically utilizing both enhancement mode and depletion mode devices upon an integrated chip.
Various electronic systems have been fabricated as large scale integrated circuits utilizing metal oxide semiconductor field effect transistors. This circuit technology includes the use of both P channel and N channel devices, as well as depletion mode and enhancement mode devices. However, for the most part, enhancement mode transistors have been utilized in such circuits in P channel configuration.
MOSFET circuits have been widely used with varying degrees of success in digital switching and amplification applications. However, a need still exists for circuitry providing high quality, high gain amplifier circuits which can be fabricated as large scale integrated circuits. In particular, a need exists in MOSFET technology for an amplifier exhibiting fast switching time in conjunction with high quality, high gain capability.